The subject of the present invention is a multicomponent kit for coloring and later removing color from fibers, especially human hair, which includes both compositions for creating a color on the fiber and compositions for reductive removal of the color.
Oxidative dyes are excellently well suited to covering relatively high proportions of gray; the oxidative dyes used for hair that is up to 50% gray are as a rule called oxidative tints, while the oxidative dyes used for a proportion of up to 100% gray or for "lightening" color are as a rule called oxidative colorings.
Direct dyes, especially nitro dyes, are widely used in nonoxidative dyes (so-called tinting compositions). Because of their small size they can penetrate the hair and color it directly--at least in the outer regions. Such tints are very gentle to the hair and as a rule last through several shampoos.
Direct dyes, especially nitro dyes, are also often used in oxidative dyes for producing certain shades or to intensify the color. It is known that colored polymers created oxidatively in the hair are generally very durable in the presence of such external factors as water, shampoo, or light. Depending on the coloring technique, they are so firmly anchored that they generally remain in the hair until the next time the hair is cut. If removal of the color is desired, then relatively aggressive chemicals must be used, such as formaldehyde sulfoxylates, hydrogen peroxide, or hydrogen peroxide addition products. This does enable extensive color removal but is hazardous to the health or involves hair damage.
Partial removal or stripping of nonoxidative tints is as a rule possible simply by washing the hair several times, but a purposeful, complete, immediate removal of the hair color is not possible in this way.
If a particular hair color is to be worn only for a short period of time, the removal of the hair color under mild, gentle conditions, both in the case of oxidative and nonoxidative colorings, is a problem that has not yet been solved.